Relationship Between Ceramic Capacitor and Frequency
The frequency characteristic of the ceramic capacitor refers to the relation between the parameters such as capacitance of the capacitor changing with the frequency. Generally speaking, when the capacitor is operated at high frequency, with the operating frequency increasing, the capacitance will decrease as the dielectric constant of the insulating medium decreases; nevertheless, the consumption will increase, and the distribution parameters of the capacitor will be affected. At high frequency operation, the performance of the capacitor will be affected by factors such as the pole piece resistance, the resistance between the lead and the pole piece, the pole piece's own inductance, the lead inductance, etc. All of these will limit the use frequency of the capacitor. In order to ensure the stability of the ceramic capacitor, the limit operating frequency of the capacitor should generally be chosen to be 1/3 - 1/2 of the natural resonant frequency of the capacitor.
The capacitance and frequency are inseparable, and the relationship should be very close. The high-capacity ceramic capacitors with a large capacitance has a poor response to high frequencies, but a good response to low frequencies is good; while the ceramic capacitors with small specifications have bad response to low frequency and very good response to high frequencies. Here is the question. What is the relationship between the size of the high-voltage ceramic capacitor and the frequency? Capacitance capacity is related to frequency. Before the resonance point, the capacitance decreases with increasing frequency. After the resonance point, the capacitance increases with frequency.
The curve relationship actually refers to the relationship between ceramic capacitance and frequency, that is, the relationship between Z (=ESR+jwL-j/wC) and frequency. In the low frequency range, the capacitance exhibits capacitive reactance characteristics; in the intermediate frequency range, mainly ESR characteristics; in the high frequency range, the inductive reactance dominates.
To put it simply, parasitic inductance and parasitic capacitance are inevitable on the device. As the frequency increases, the reactance of the capacitor will become closer to zero, and the reactance value of the parasitic inductor will gradually increase. Finally, the reactance of the capacitor will exceed the capacitance and the whole device will be inductive. The larger the capacitance, the closer the high-frequency reactance value is to 0, and the easier it is to be surpassed by its own parasitic inductance.
Similarly, the inductor may also be capacitive at high frequencies, and the larger the inductance, the more likely it is to happen. The size and frequency of the capacitors are also related to their manufacturing process! Allicdata Electronic specialize in the production of safety capacitors, varistors, ceramic capacitors, film capacitors, if you are sourcing the products, please go to our website contact us, we will try our best to solve it for you.
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